Compare Elements

Compare two chemical elements side by side across 19 atomic and physical properties.

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Element comparison
Property H Hydrogen K Potassium
Atomic Number 1 lower 19 lower
Symbol H different K different
Name Hydrogen different Potassium different
Atomic Mass 1.008 lower 39.0983 lower
Category Reactive Nonmetals different Alkali Metals different
Period 1 lower 4 lower
Group 1 same value 1 same value
Block s-Block same value s-Block same value
Standard State Gas different Solid different
Electronegativity 2.2 higher 0.82 higher
Atomic Radius 120 lower 275 lower
Ionization Energy 13.598 higher 4.341 higher
Electron Affinity 0.754 higher 0.501 higher
Oxidation States +1, -1 different +1 different
Melting Point 13.81 K (-259.34 °C) lower 336.53 K (63.38 °C) lower
Boiling Point 20.28 K (-252.87 °C) lower 1032 K (758.85 °C) lower
Density 0.0001 lower 0.89 lower
Electron Configuration 1s1 different [Ar]4s1 different
Year Discovered 1766 different 1807 different

higher lower